Josh Hartnett Reveals He Had Intense Food Poisoning While Filming 'Verity'

Josh Hartnett says a terrible bout of food poisoning made it almost impossible for him to walk ... and it struck at the most inopportune time, because he was filming "Verity."

During a press tour for the new movie, Josh's costar Anne Hathaway recalled his crappy health issue as "so much worse" than projectile vomiting.

Josh says he couldn't walk for 10 days because his muscles were so cramped from all the vomiting and dehydration ... which made filming the flick all the more difficult.

Apparently, it was so bad that he needed to be tended to when he was off-camera ... and if he wasn't in a scene, he was flat on his back.

If this is sounding like déjà poo vu, that's because he infamously suffered some serious tummy troubles back in 2009 while at the Chateau Marmont ... with TMZ obtaining the audio from when he called 911 and told dispatchers he was dealing with vomiting and diarrhea.

BTW, he denied making that call when Charlie caught up with him in 2017.

Fast forward to today, and it sounds like the guy caught the bug once again.